A revolutionary militant is killed during the repression of May 1945. His son, who is unaware of the real circumstances of the murder, ends up being attached to the ideal for which his father died.

Following a robbery in a circus, a young mobster, Jean, is arrested by Inspector Borelli. The thug denies involvement. To compel him to sign a full confession, Inspector Muller encourages the suspect to get married for - he says - to move the jury. This being done, he lets Jean believe that he can spend a moment alone with his wife; but then, Inspector Borelli blackmails him: "If you sign your confession, you can spend a moment with her." After being beaten, Jean signs a confession. It is then that a new blackmail intervenes: "the name of the accomplice?", asks the inspector. But the thug refuses to denounce the latter and ends up refusing the bargain dupes. While the guards drive him back to prison, his wife cuts his veins, breaking the career of the bad policeman.

After saving an infant of royal blood, knight Brancaleone forms a new army and sets out to return the baby to his father: a prince fighting in the Crusades.